In the design of motor vehicles it is almost mandatory that the gear shifting apparatus or transmission be located directly at the output shaft of the prime motor. In many cases it is desirable to locate the gear shift lever at a position substantially removed from the transmission. Such is often the case in connection with an automobile in which the motor is mounted adjacent the rear wheels, as in the case of the Volkswagon automobile. In such case, it is common practice to use control rods leading from the shift lever to the transmission. Such control rods, of course, introduce limitations into the system; for instance, the length of the rods is somewhat limited. Furthermore, the rods must pass through a straight path, thus substantially limiting the nature of the automotive design. Remote control devices have been developed, of course, and these are mostly of an electrical nature, but are only practical where the application is a very expensive one and warrants the cost of electrical servo-motors and the like. The problem arises particularly in connection with the design of earth moving equipment where, first of all, a rugged inexpensive design is desired and, secondly, the operator's cab and the drive mechanism are located at opposite ends of the vehicle with intricate machinery such as scrapers and the like located between them, so that it is impossible to provide a straight path for cables. Futhermore, cables and levers wear out and become inoperative due to the presence of dust and moisture. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a remote shift operating through hydraulic fluid.
Another object of this invention is the provision of a remote shift in which a connection between the gear shift lever and the transmission has a path which is of unlimited length and unlimited shape.
A further object of the present invention is the provision of a remote shift using hydraulic principles, which shift is simple in construction, inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
A still further object of the invention is the provision of a remote shift in which there is no looseness or backlash between the shift handle and the actual transmission; in which the shifting action has the feel of a direct transmission shift; in which gear shifting can take place very rapidly; in which two different modes of shifting are available selectively; in which the weight of the apparatus is substantially reduced; in which the gear shift handle may be mounted adjustably on the vehicle to allow it to be positioned in accordance with the requirements of the driver.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.